Development Thread Testing of Audio Latency Fix branch

[JMC47]

I get about half the audio latency I do in most games. Some games are oddly unaffected as I said before. I haven't noticed any popular games be unaffected. For those who want an easy way to test, run two copies of Dolphin, old build and test build, and compare how long the audio seems to wait. The newer build should (always) be the lower latency audio you here, where as the second time you hear a sound will be the older build.

This does not fix backend latency, only the mixer latency, thus dsound will still suck.